Add lucid sleep flag and debugging helper

chrome/browser/chromeos/power/light_bar.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_CHROMEOS_POWER_LIGHT_BAR_H_
+#define CHROME_BROWSER_CHROMEOS_POWER_LIGHT_BAR_H_
+
+#include "base/files/file_path.h"
+#include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/power_manager_client.h"
+
+namespace chromeos {
+
+// Flashes the light bar (on systems that have one) whenever the system comes up
+// in dark resume.
+class CHROMEOS_EXPORT LightBar : public PowerManagerClient::Observer {
+ public:
+  LightBar();
+  virtual ~LightBar();
+
+  // PowerManagerClient::Observer implementation.
+  virtual void DarkSuspendImminent() OVERRIDE;
+
+ private:
+  // Path to control the light bar.
+  base::FilePath control_path_;
+
+  // True if the system has a light bar.
+  bool has_light_bar_;
+
+  DISALLOW_COPY_AND_ASSIGN(LightBar);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_POWER_LIGHT_BAR_H_